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Change a Flat Bike Tire

By Attila Horvath

Schrader and Presta
Schrader valves are like the ones on a car. Presta valves are taller, skinnier and have a little nut to loosen before inflation.

Patching a tube
Small tube punctures can be patched. Any place that sells bikes will sell patch kits. They include a set of patches, sandpaper, rubber cement and instructions. Be aware that large tears, holes along tube seams and broken valve stems can’t be fixed with a patch, which is why you should always have an extra tube (or two) with you when you ride.

Change a Flat Bike Tire photo gallery

Even the most mechanically-challenged rider can change a flat bike tire. Master this skill and you won’t be forced to walk home.

An ounce of prevention is worth a pound (per square inch) of cure. Obviously, don’t ride through broken glass and other potentially damaging debris. Sarai Snyder of Reser Bicycle in Newport, KY gives another tip: “Keep your tire pressure up. Tires need to be inflated once a week.” Under-inflated tires are more likely to puncture. Tires have a recommended maximum PSI (pounds per square inch) written on the sidewall. Pump your tires to that level.

Fools don’t carry the tools.* Carry this stuff in a little bag that attaches under your bike seat:

Make sure your spare tube is the right size, and has the right valve style (Schrader or Presta) for your rim. Many punctures can be patched using a patch kit, though Sarai advises, “The safest bet is to replace the tube. A patch is not reliable and sometimes hard to get on right.”

Remove the wheel. With a quick-release wheel attachment, flip the lever to the open position (it’s likely marked “open” and “closed) and loosen the nut on the opposite side of the lever by hand. For bikes with a nut and bolt attachment, you’ll need to have a couple of wrenches of the correct size. To provide enough space for the tire to pass through the brake pads, you’ll need to release the brake arms. Most road bikes have a lever to flip up on the brake arm. On most mountain bikes, squeeze the levers together by hand and detach the cable from the brake arm. If you’re removing the rear wheel, you need to pull back on the derailleur to help disengage the chain.

Remove the tire from the rim and remove the tube. If the tube still has some air in it, let it out. Insert the lever between the tire and rim to pry them apart. For tight tires, you’ll need to insert more levers. Slide the second (or third) lever around the rim to “unseat” the tire. Do not completely remove the tire from the rim. One side is enough. Push the valve stem out first, and pull out the tube.

Inspect the tire and rim. Whatever punctured the tube may be stuck in the tire. Inspect the tire, inside and out, for thorns or other junk. Make sure that your rim strip (a ribbon of tape to provide a cushion between the ends of your spokes and the tube) is in place.

Install the new tube and mount the tire. Pump just enough air into your new tube to make it round. Insert the valve stem into the rim first, but keep it loose so it can move when you pump up the tube. Then gently push the rest of the tube into the tire. Be careful to not pinch the tube between the rim and tire. Do as much as you can by hand. If you need to use the tire lever to pop the edge of the tire into place, take care to not damage your new tube by pinching it. If the tube is not poking out or bunched up and the valve is straight, you’re ready to inflate the tire to the recommended PSI and install the wheel back on the bike. Don’t forget to attach your brake.

Practice at home. Don’t wait till you have a blowout on the road to learn. Familiarity with these tools and skills will make your job easier.

*Fools don’t know their tools
Fancier compact air pumps are available with built-in pressure gauges. Many have two settings. One is for getting the initial volume of air into the tube and a second to top it off. Expect to spend more time and effort inflating your tube using a compact pump compared to a large stand-up floor pump, and make sure you’re clear on how your particular pump secures to the valve; different styles abound.

Plastic tire levers are used to pry the edge of your tire away from the rim so you can get your damaged tube out and replace the tire. Don’t use a screwdriver or something that will likely damage your rim and/or tube.

A pressure gauge is an optional addition to your tool kit if your pump doesn’t have a gauge built in. You may need to get an adaptor for your gauge to fit onto a Presta valve.